B'Consider two undirected graphs G_1 and G_2 . Every node in G_1 and in G_2 has a label. Doremy calls G_1 and G_2 similar if and only if: Now Doremy gives you two trees T_1 and T_2 with n nodes, labeled from 1 to n . You can do the following operation any number of times: Now Doremy is wondering how many distinct T_1 you can get after any number of operations. Can you help her find the answer? Output the answer modulo 10^9+7 . The input consists of multiple test cases. The first line contains a single integer t ( 1 <= t <= 2 cdot 10^4 ) -- the number of test cases. The description of the test cases follows. The first line contains an integer n ( 2 <= n <= 10^5 ) -- the number of nodes in the trees T_1 and T_2 . Each of the following n-1 lines contain two integers u,v ( 1 <= u,v <= n ), representing an undirected edge in T_1 . It is guaranteed these edges form a tree. Each of the following n-1 lines contain two integers u,v ( 1 <= u,v <= n ), representing an undirected edge in T_2 . It is guaranteed these edges form a tree. It is guaranteed that the sum of n does not exceed 2 cdot 10^5 . For each test case, you should output a single line with an integer, representing the number of distinct T_1 after any number of operations, modulo 10^9+7 . In the first test case, there is at most one distinct T_1 having the only edge (1,2) . In the second test case, you can choose the edge set {(1,3),(2,3) } in T_1 , the edge set {(1,2),(2,3) } in T_2 and swap them. So T_1 can be 1-3-2 or 1-2-3 . In the third test case, there are 4 distinct T_1 , as the following pictures. '...